reltool

MODULE

reltool

MODULE SUMMARY

Main API of the Reltool application

DESCRIPTION

This is an interface module for the Reltool application.

Reltool is a release management tool. It analyses a
given Erlang/OTP installation and determines various dependencies
between applications. The graphical frontend depicts the
dependencies and enables interactive customization of a target
system. The backend provides a batch interface for
generation of customized target systems.

The tool uses an installed Erlang/OTP system as input.
root_dir is the root directory of the analysed system and
it defaults to the system executing reltool. Applications
may also be located outside root_dir. lib_dirs
defines library directories where additional applications
may reside and it defaults to the directories
listed by the operating system environment variable
ERL_LIBS. See the module code for more info.

An application directory AppDir under a library
directory is recognized by the existence of an AppDir/ebin
directory. If this does not exist, reltool will not
consider AppDir at all when looking for applications.

It is recommended that application directories are named as the
application, possibly followed by a dash and the version
number. For example myapp or myapp-1.1.

Finally single modules and entire applications may be read from
Escripts.

This is the main option and it controls the configuration
of reltool. It can either be a sys tuple or
a name of a file containing a sys tuple.

trap_exit

This option controls the error handling behavior of
reltool. By default the window processes traps
exit, but this behavior can altered by setting
trap_exit to false.

wx_debug

This option controls the debug level of wx. As its
name indicates it is only useful for debugging. See
wx:debug/1 for more info.

Besides the already mentioned source parameters root_dir
and lib_dirs, the following system (sys) level
options are supported:

erts

Erts specific configuration. See application level options
below.

escript

Escript specific configuration. An escript has a mandatory
file name and escript level options that are described
below.

app

Application specific configuration. An application has a
mandatory name and application level options that are
described below.

mod_cond

This parameter controls the module inclusion policy. It
defaults to all which means that if an application is
included (either explicitly or implicitly) all modules in that
application will be included. This implies that both modules
that exist in the ebin directory of the application,
as well as modules that are named in the app file will
be included. If the parameter is set to ebin, both
modules in the ebin directory and derived modules are
included. If the parameter is set to app, both modules
in the app file and derived modules are included.
derived means that only modules that are used by other
included modules are included. The mod_cond setting on
system level is used as default for all applications.

incl_cond

This parameter controls the application and escript
inclusion policy. It defaults to derived which means
that the applications that do not have any explicit
incl_cond setting, will only be included if any other
(explicitly or implicitly included) application uses it. The
value include implies that all applications and
escripts that do not have any explicit incl_cond
setting will be included. exclude implies that all
applications and escripts that do not have any explicit
incl_cond setting will be excluded.

boot_rel

A target system may have several releases but the one given
as boot_rel will be used as default when the system is
booting up.

rel

Release specific configuration. Each release maps to a
rel, script and boot file. See the
module systools for more info about the details. Each
release has a name, a version and a set of applications with a
few release specific parameters such as type and included
applications.

relocatable

This parameter controls whether the erl executable
in the target system should automatically determine where it
is installed or if it should use a hardcoded path to the
installation. In the latter case the target system must be
installed with reltool:install/2 before it can be
used. If the system is relocatable, the file tree containing
the target system can be moved to another location without
re-installation. The default is true.

profile

The creation of the specification for a target system is
performed in two steps. In the first step a complete
specification is generated. It will likely contain much more
files than you are interested in in your customized target
system. In the second step the specification will be filtered
according to your filters. There you have the ability to
specify filters per application as well as system wide
filters. You can also select a profile for your
system. Depending on the profile, different default
filters will be used. There are three different profiles to
choose from: development, embedded and
standalone. development is default. The
parameters that are affected by the profile are:
incl_sys_filters, excl_sys_filters,
incl_app_filters and excl_app_filters.

app_file

This parameter controls the default handling of the
app files when a target system is generated. It
defaults to keep which means that app files are
copied to the target system and their contents are kept as
they are. strip means that a new app file is
generated from the contents of the original app file
where the non included modules are removed from the
file. all does also imply that a new app file is
generated from the contents of the original app file,
with the difference that all included modules are added to the
file. If the application does not have any app file a
file will be created for all but not for keep
and strip.

debug_info

The debug_info parameter controls whether the debug
information in the beam file should be kept (keep) or
stripped strip when the file is copied to the target
system.

excl_lib

Warning

This option is experimental.

If the excl_lib option is set to otp_root
then reltool will not copy anything from the Erlang/OTP
installation ($OTP_ROOT) into the target structure. The goal
is to create a "slim" release which can be used together with
an existing Erlang/OTP installation. The target structure will
therefore only contain a lib directory with the
applications that were found outside of $OTP_ROOT (typically
your own applications), and a releases directory with
the generated .rel,.script and .boot
files.

When starting this release, three things must be specified:

Which releases directory to use

Tell the release handler to use the releases
directory in our target structure instead of
$OTP_ROOT/releases. This is done by setting the SASL
environment variable releases_dir, either from the
command line (-sasl releases_dir
<target-dir>/releases) or in
sys.config.

Which boot file to use

The default boot file is $OTP_ROOT/bin/start,
but in this case we need to specify a boot file from our
target structure, typically
<target-dir>/releases/<vsn>/<RelName>. This
is done with the -boot command line option to
erl

The location of our applications

The generated .script (and .boot) file uses the
environment variable $RELTOOL_EXT_LIB as prefix for
the paths to all applications. The -boot_var option
to erl can be used for specifying the value of this
variable, typically -boot_var RELTOOL_EXT_LIB
<target-dir>/lib.

This parameter normally contains a list of regular
expressions that controls which files in the system
should be included. Each file in the target system must match
at least one of the listed regular expressions in order to be
included. Further the files may not match any filter in
excl_sys_filters in order to be included. Which
application files should be included is controlled with
the parameters incl_app_filters and
excl_app_filters. This parameter defaults to
[".*"].

excl_sys_filters

This parameter normally contains a list of regular
expressions that controls which files in the system should
not be included in the target system. In order to be
included, a file must match some filter in
incl_sys_filters but not any filter in
excl_sys_filters. This parameter defaults to
[].

incl_app_filters

This parameter normally contains a list of regular
expressions that controls which application specific files
that should be included. Each file in the application must
match at least one of the listed regular expressions in order
to be included. Further the files may not match any filter in
excl_app_filters in order to be included. This
parameter defaults to [".*"].

excl_app_filters

This parameter normally contains a list of regular
expressions that controls which application specific files
should not be included in the target system. In order to
be included, a file must match some filter in
incl_app_filters but not any filter in
excl_app_filters. This parameter defaults to
[].

incl_archive_filters

This parameter normally contains a list of regular
expressions that controls which top level directories in an
application should be included in an archive file (as
opposed to being included as a regular directory outside the
archive). Each top directory in the application must match at
least one of the listed regular expressions in order to be
included. Further the files may not match any filter in
excl_app_filters in order to be included. This
parameter defaults to [".*"].

excl_archive_filters

This parameter normally contains a list of regular
expressions that controls which top level directories in an
application should not be included in an archive file. In
order to be included in the application archive, a top
directory must match some filter in incl_archive_filters
but not any filter in excl_archive_filters. This
parameter defaults to ["^include$","^priv$"].

archive_opts

This parameter contains a list of options that are given to
zip:create/3 when application specific files are
packaged into an archive. Only a subset of the options are
supported. The most useful options in this context are the ones
that control which types of files should be compressed. This
parameter defaults to [].

On application (escript) level, the following options are
supported:

incl_cond

The value of this parameter overrides the parameter with the
same name on system level.

On application (app) level, the following options are
supported:

vsn

The version of the application. In an installed system there may
exist several versions of an application. The vsn parameter
controls which version of the application will be chosen.

This parameter is mutual exclusive with lib_dir. If
vsn and lib_dir are both omitted, the latest version
will be chosen.

Note that in order for reltool to sort application versions
and thereby be able to select the latest, it is required that
the version id for the application consits of integers and
dots only, for example 1, 2.0 or
3.17.1.

lib_dir

The directory to read the application from. This parameter
can be used to point out a specific location to fetch the
application from. This is useful for instance if the parent
directory for some reason is no good as a library directory on
system level.

This parameter is mutual exclusive with vsn. If
vsn and lib_dir are both omitted, the latest version
will be chosen.

Note that in order for reltool to sort application versions
and thereby be able to select the latest, it is required that
the version id for the application consits of integers and
dots only, for example 1, 2.0 or
3.17.1.

mod

Module specific configuration. A module has a mandatory
name and module level options that are described below.

mod_cond

The value of this parameter overrides the parameter with the
same name on system level.

incl_cond

The value of this parameter overrides the parameter with the
same name on system level.

app_file

The value of this parameter overrides the parameter with the
same name on system level.

debug_info

The value of this parameter overrides the parameter with the
same name on system level.

incl_app_filters

The value of this parameter overrides the parameter with the
same name on system level.

excl_app_filters

The value of this parameter overrides the parameter with the
same name on system level.

incl_archive_filters

The value of this parameter overrides the parameter with the
same name on system level.

excl_archive_filters

The value of this parameter overrides the parameter with the
same name on system level.

archive_opts

The value of this parameter overrides the parameter with the
same name on system level.

On module (mod) level, the following options are
supported:

incl_cond

This parameter controls whether the module is included or not. By
default the mod_cond parameter on application and system level
will be used to control whether the module is included or not. The
value of incl_cond overrides the module inclusion policy.
include implies that the module is included, while
exclude implies that the module is not included.
derived implies that the module is included if it is used
by any other included module.

debug_info

The value of this parameter overrides the parameter with
the same name on application level.

Create the actual target system from a specification
generated by reltool:get_target_spec/1. The creation of
the specification for a target system is performed in two
steps. In the first step a complete specification will be
generated. It will likely contain much more files than you are
interested in in your target system. In the second step the
specification will be filtered according to your filters. There
you have the ability to specify filters per application as well
as system wide filters. You can also select a profile for
your system. Depending on the profile, different default
filters will be used.

The top directories bin, releases and
lib are treated differently from other files. All other
files are by default copied to the target system. The
releases directory contains generated rel,
script, and boot files. The lib directory
contains the applications. Which applications are included
and if they should be customized (archived, stripped from debug
info etc.) is specified with various configuration
parameters. The files in the bin directory are copied
from the erts-vsn/bin directory, but only those files
that were originally included in the bin directory of the
source system.

If the configuration parameter relocatable was set to
true there is no need to install the target system with
reltool:install/2 before it can be started. In that case
the file tree containing the target system can be moved without
re-installation.

In most cases, the RootDir parameter should be set to
the same as the root_dir configuration parameter used in
the call to reltool:get_target_spec/1
(or code:root_dir() if the configuration parameter is not
set). In some cases it might be useful to evaluate the same
target specification towards different root directories. This
should, however, be used with great care as it requires
equivalent file structures under all roots.

Get reltool configuration. Normally, only the explicit
configuration parameters with values that differ from their
defaults are interesting. But the builtin default values can be
returned by setting InclDefaults to true. The
derived configuration can be returned by setting
InclDerived to true.